I can't figure out how to set up this problem...You have a large amount of 8.00 M stock solution. You need 1.80L of 3.00 M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?

Answer 1

The amount of solute in 1L of 1.80M solution would be the same as that in 1.80/8.00L of the 8.00M solution.

So, take 0.225L of the 8M, and fill the flask to 1L.

Answer 2

Sorry. Got my numbers mixed up.

The ratio is 3/8.
The solute in 1L of 3M solution is the same as in 3/8L of 8M.

So, take 3/8*1.8 = 0.675L of the 8M solution, and fill the flask to 1.80L